/////////////////////////////  GPL LICENSE NOTICE  /////////////////////////////

//  crt-royale: A full-featured CRT shader, with cheese.
//  Copyright (C) 2014 TroggleMonkey <trogglemonkey@gmx.com>
//
//  This program is free software; you can redistribute it and/or modify it
//  under the terms of the GNU General Public License as published by the Free
//  Software Foundation; either version 2 of the License, or any later version.
//
//  This program is distributed in the hope that it will be useful, but WITHOUT
//  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
//  more details.
//
//  You should have received a copy of the GNU General Public License along with
//  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
//  Place, Suite 330, Boston, MA 02111-1307 USA


/////////////////////////////  SETTINGS MANAGEMENT  ////////////////////////////

#include "../user-settings.h"
#include "derived-settings-and-constants.h"
#include "bind-shader-params.h"


//////////////////////////////////  INCLUDES  //////////////////////////////////

#include "../../../include/gamma-management.h"
#include "bloom-functions.h"
#include "phosphor-mask-resizing.h"
#include "scanline-functions.h"


/////////////////////////////////  STRUCTURES  /////////////////////////////////

struct orig
{
    float2 tex_coord;
    uniform float2 video_size;
    uniform float2 texture_size;
    uniform float2 output_size;
    uniform sampler2D texture;
};

struct input
{
    float2 video_size;
    float2 texture_size;
    float2 output_size;
    float frame_count;
    float frame_direction;
    float frame_rotation;
};

struct out_vertex
{
    float4 position                     : POSITION;
    float2 video_uv                     : TEXCOORD0;
    float2 scanline_tex_uv              : TEXCOORD1;
    float2 halation_tex_uv              : TEXCOORD2;
    float2 brightpass_tex_uv            : TEXCOORD3;
    float2 bloom_tex_uv                 : TEXCOORD4;
    float2 bloom_dxdy                   : TEXCOORD5;
    float bloom_sigma_runtime           : TEXCOORD6;
};


////////////////////////////////  VERTEX SHADER  ///////////////////////////////

out_vertex main_vertex
(
    float4 position : POSITION,
    float4 color    : COLOR,
    float2 tex_uv   : TEXCOORD0,

    uniform float4x4 modelViewProj,
    uniform input IN,
    uniform orig ORIG_LINEARIZED,
    uniform orig HALATION_BLUR,
    uniform orig MASKED_SCANLINES,
    uniform orig BRIGHTPASS
)
{
    out_vertex OUT;
    OUT.position = mul(modelViewProj, position);

    //  Our various input textures use different coords:
    const float2 video_uv = tex_uv * IN.texture_size/IN.video_size;
    OUT.video_uv = video_uv;
    OUT.scanline_tex_uv = video_uv * MASKED_SCANLINES.video_size /
        MASKED_SCANLINES.texture_size;
    OUT.halation_tex_uv = video_uv * HALATION_BLUR.video_size /
        HALATION_BLUR.texture_size;
    OUT.brightpass_tex_uv = video_uv * BRIGHTPASS.video_size /
        BRIGHTPASS.texture_size;
    OUT.bloom_tex_uv = tex_uv;

    //  We're horizontally blurring the bloom input (vertically blurred
    //  brightpass).  Get the uv distance between output pixels / input texels
    //  in the horizontal direction (this pass must NOT resize):
    OUT.bloom_dxdy = float2(1.0/IN.texture_size.x, 0.0);

    //  Calculate a runtime bloom_sigma in case it's needed:
    const float mask_tile_size_x = get_resized_mask_tile_size(
        IN.output_size, IN.output_size * mask_resize_viewport_scale, false).x;
    OUT.bloom_sigma_runtime = get_min_sigma_to_blur_triad(
        mask_tile_size_x / mask_triads_per_tile, bloom_diff_thresh);
    return OUT;
}


///////////////////////////////  FRAGMENT SHADER  //////////////////////////////

float4 main_fragment(in out_vertex VAR, uniform input IN,
    uniform orig MASKED_SCANLINES,
    uniform orig HALATION_BLUR,
    uniform orig BRIGHTPASS,
    uniform sampler2D bloom_texture : TEXUNIT0) : COLOR
{
    //  Blur the vertically blurred brightpass horizontally by 9/17/25/43x:
    const float bloom_sigma = get_final_bloom_sigma(VAR.bloom_sigma_runtime);
    const float3 blurred_brightpass = tex2DblurNfast(bloom_texture,
        VAR.bloom_tex_uv, VAR.bloom_dxdy, bloom_sigma);

    //  Sample the masked scanlines.  Alpha contains the auto-dim factor:
    const float3 intensity_dim =
        tex2D_linearize(MASKED_SCANLINES.texture, VAR.scanline_tex_uv).rgb;
    const float auto_dim_factor = levels_autodim_temp;
    const float undim_factor = 1.0/auto_dim_factor;

    //  Calculate the mask dimpass, add it to the blurred brightpass, and
    //  undim (from scanline auto-dim) and amplify (from mask dim) the result:
    const float mask_amplify = get_mask_amplify();
    const float3 brightpass = tex2D_linearize(BRIGHTPASS.texture,
        VAR.brightpass_tex_uv).rgb;
    const float3 dimpass = intensity_dim - brightpass;
    const float3 phosphor_bloom = (dimpass + blurred_brightpass) *
        mask_amplify * undim_factor * levels_contrast;

    //  Sample the halation texture, and let some light bleed into refractive
    //  diffusion.  Conceptually this occurs before the phosphor bloom, but
    //  adding it in earlier passes causes black crush in the diffusion colors.
    const float3 diffusion_color = levels_contrast * tex2D_linearize(
        HALATION_BLUR.texture, VAR.halation_tex_uv).rgb;
    const float3 final_bloom = lerp(phosphor_bloom,
        diffusion_color, diffusion_weight);

    //  Encode and output the bloomed image:
    return encode_output(float4(final_bloom, 1.0));
}